Original Article

Fumed Silica Particle Deagglomeration Associated with Instrument Techniques

Abstract

Fumed silica, due to the thixotropic properties and low thermal conductivity, is used in insulation products. Exposure to crystalline silica is of most concern and there is also evidence that exposure to nanometer-sized fumed silica may lead to adverse health outcomes. Workers’ exposure to aerosolized fumed silica and other potentially hazardous materials are commonly assessed using direct-reading instruments. These instruments often contain an aerosol pre-separator cyclone, which by dispersing agglomerated particles, may cause variations in the reading values. This study investigates the effect of these cyclones on the measurements by comparing three instruments for airborne fumed silica that was generated using manual and automatic manipulation methods of manual pouring and automatic stirring. The results from these experiments showed that the measured concentration of nano-sized fumed silica increased with the use of cyclone. This may attribute to the residual particles remained inside the cyclone or attached on its wall in the particle separation process, which needs to be considered in and the corresponding correction should be made when measuring the concentration of fumed silica with an instrument that uses a cyclone as a pre-separator.

. Hartley, P. A.; Parfitt, G. D.; Pollack, L. B., The role of the van der Waals force in the agglomeration of powders containing submicron particles. Powder Technology 1985, 42, (1).

. Corn, M., The Adhesion of Solid Particles to Solid Surfaces, I. a Review. Journal of the Air Pollution Control Association 1961, 11, (11).

. Irfan, A.; Cauchi, M.; Edmands, W.; Gooderham, N.; Njuguna, J.; Zhu, H., Assessment of Temporal Dose-Toxicity Relationship of Fumed Silica Nanoparticle in Human Lung A549 Cells by Conventional Cytotoxicity and H-NMR-Based Extracellular Metabonomic Assays. Toxicological Sciences, 2014, 138, (2).

. Merkel, T. C.; Freeman, B. D.; Spontak, R. J.; He, Z.; Pinnau, I.; Meakin, P.; Hill, A. J., Ultrapermeable, Reverse-Selective Nanocomposite Membranes. Science 2002, 296, (5567).

. Raghavan, S.; Khan, S., Shear-Thickening Response of Fumed Silica Suspensions under Steady and Oscillatory Shear. Journal of Colloid and Interface Science 1997, 185, (1).

. Vitums, V. C.; Edwards, M. J.; Niles, N. R.; Borman, J. O.; Lowry, R. D., Pulmonary Fibrosis from Amorphous Silica Dust, A Product of Silica Vapor. Archives of Environmental and Occupational Health 1977, 32, (2).

. Sandberg, W.; Lag, M.; Holme, J.; Friede, B.; Maurizio, G.; Kruszewski, M.; Schwarze, P.; Skuland, T.; Refsnes, M., Comparison of non-crystalline silica nanoparticles in IL-1β release from macrophages. Particle and Fibre Toxicology 2012, 9, (32).

. Ren, L.; Zhang, J.; Zou, Y.; Zhang, L.; Wei, J.; Shi, Z.; Li, Y.; Guo, C.; Sun, Z.; Zhou, X., Silica nanoparticles induce reversible damage of spermatogenic cells via RIPK1 signal pathways in C57 mice. Int. J. Nanomedicine 2016, 24, (11).

. Sun, B.; Wang, X.; Liao, Y. P.; Ji, Z.; Chang, C. H.; Pokhrel, S.; Ku, J.; Liu, X.; Wang, M.; Dunphy, D. R.; Li, R.; Meng, H.; Madler, L.; Brinker, J.; Nel, A. E.; Xia, T., Repetitive Dosing of Fumed Silica Leads to Profibrogenic Effects through Unique Structure−Activity Relationships and Biopersistence in the Lung. ACSnano 2016, 10, (8).

. Kaewamatawong, T.; Kawamura, N.; Okajima, M.; Sawada, M.; Morita, T.; Shimada, A., Acute Pulmonary Toxicity Caused by Exposure to Colloidal Silica: Particle Size Dependent Pathological Changes in Mice. Toxicology Pathology 2005, 33, (7).

. Zhang, H.; Dunphy, D. R.; Jiang, X.; Meng, H.; Sun, B.; Tarn, D.; Xue, M.; Wang, X.; Lin, S.; Ji, Z.; Li, R.; Garcia, F. L.; Yang, J.; Kirk, M. L.; Xia, T.; Zink, J. I.; Nel, A.; Brinker, C. J., Processing pathway dependence of amorphous silica nanoparticle toxicity: colloidal versus pyrolytic. Journal of the American Chemical Society 2012, 134, (38).

. Yamada, M.; Takaya, M.; Ogura, I., Performance evaluation of newly developed portable aerosol sizers used for nanomaterial aerosol measurements. Industrial Health 2015, 53, (6).

. Kousaka, Y.; Okuamama, K.; Shimizu, A.; Yoshida, T., Dispersion Mechanism of Aggregate Particles in Air. Journal of Chemical Engineering of Japan 1979, 12, (2).

. Tsai, C.; Theisen, D., A Sampler Designed for Nanoparticles and Respirable Particles with Direct Analysis Feature. J Nanopart Res 2018, 20, (209).

. Schindelin, J.; Arganda-Carreras, I.; Frise, E.; Kaynig, V.; Longair, M.; Pietzsch, T.; Preibisch, S.; Rueden, C.; Saalfeld, S.; Schmid, B., Fiji: an open-source platform for biological-image analysis. Nature methods 2012, 9, (7), 676-682.

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IssueVol 10 No 3 (2018) QRcode
SectionOriginal Article(s)
Published2018-08-30
Keywords
fumed silica, deagglomeration, cyclone, real time instrument, sampling

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How to Cite
1.
KHATTAK J, SHIN N, RHINE WE, GOULD G, TSAI CS. Fumed Silica Particle Deagglomeration Associated with Instrument Techniques. Int J Occup Hyg. 2018;10(3):124-134.